Optimal Target Low-density Lipoprotein Cholesterol Level for Small Vessel Occlusion Stroke

Inclusion Criteria: 1. Age 19 years or older 2. Patients with objectively confirmed small vessel occlusive infarctions in the subcortical or brainstem regions, identified through neuroimaging (MRI or CT) 3. Patients with a history of symptomatic ischemic stroke caused by the lesion described in 2), occurring within 180 days prior to enrollment 4. Patients or guardians who agree to the study protocol and sign with informed consent Exclusion Criteria: 1. Extracranial or intracranial large artery stenosis ≥50% 2. History of atherosclerotic ischemic stroke or transient ischemic attack 3. Documented coronary artery disease 4. Documented peripheral artery disease or aortic atherosclerotic disease 5. Diabetes with one or more of the following: duration ≥10 years; ≥2 major risk factors (men ≥45 years, women ≥55 years; family history of premature atherosclerotic cardiovascular disease; hypertension; current smoking; or HDL cholesterol \<40 mg/dL); or known evidence of target organ damage (albuminuria, estimated glomerular filtration rate \<60 mL/min per 1.73 m², retinopathy, neuropathy, or left ventricular hypertrophy) 6. Baseline LDL cholesterol \<70 mg/dL in the absence of lipid-lowering therapy (statins, ezetimibe, PCSK9 inhibitors, etc.) 7. Patients contraindicated for statin use (e.g., active liver disease, serum transaminase levels elevated more than three times the normal limit, muscle disorders, hypersensitivity to statins, or taking medications contraindicated for use with statins) 8. Women who are pregnant, breastfeeding, or intending to become pregnant during the study period 9. Deemed unsuitable for participation in the study for more than four years, as per the investigators' discretion